Temple of Ranma's Sailor Senshi Seifuku

I'm trying to remeber a fic that I read which some of the main plot points where

Transgender Harry
Snape/Harry pairing
Snape/Harry buying a house in a muggle town
Ron getting expelled

Transgender Harry

Only transgender i can recall was Hermione ( fairly decent IIRC ). Seems to be a rare plotpoint for HP-verse.

Snape/Harry pairing

*Shudders in horror*

That is seriously *something unmentionable*. In at least two ways.

The Snape part weirded me out about that fic, but sometimes you cant have one without the other, and trans harry fics are super limited.

Only one fic springs to mind when it comes to transgender which is The Many Faces of Harry Potter in which Harry has multiple personality disorder and when differant personalities emerge his body changes to match and several are girls. Harry, the main personality realises he wants to be a girl and so forces his body to change which is much harder than the other changes. Cant member much else about the story but it's pretty good and original and the author also has MPD so they know what they are writing about. I dont think she has anything to do with snape. Ther are a few stories in which Harry is changed into a girl and accepts it easily and it's suggested he was transgendered but it's only a very brief mention.

Edit:
I did a search and found Holly which seems to fit all your criteria, a quick scan shows transgendered, with snape and Ron gets expelled. If it's not this one then I'll have another look.

https://www.fanfiction.net/s/2413355/1/Moon-s-Revenge-for-Betrayal — This has a genderswap Harry and SS/HP. Touches base with SM, as well. Only one chapter, though, and almost certainly a dead fic: Last updated 2005-05-28.